using System;
using System.Collections.Generic;
using Minesweeper.Core;
using TMPro;
using UnityEngine;
using UnityEngine.UI;

namespace Minesweeper.Presentation.Views
{
    public sealed class GameView : MonoBehaviour, IGameView
    {
        [SerializeField] private GameObject gameRoot;
        [SerializeField] private GameObject pauseRoot;
        [SerializeField] private RectTransform boardPanel;
        [SerializeField] private GridLayoutGroup gridLayoutGroup;
        [SerializeField] private Button pauseButton;
        [SerializeField] private Button restartButton;
        [SerializeField] private Button resumeButton;
        [SerializeField] private Button mainMenuButton;
        [SerializeField] private TMP_Text timerText;
        [SerializeField] private TMP_Text mineText;
        [SerializeField] private float spacing = 2f;
        [SerializeField] private float basePixelsPerUnitCellSize = 32f;

        private readonly Dictionary<int, CellView> cellsByCoordinate = new Dictionary<int, CellView>();
        private bool boardInputEnabled = true;
        private float currentPixelsPerUnitMultiplier = 1f;

        public event Action RestartRequested;
        public event Action GoToMenuRequested;
        public event Action PauseRequested;
        public event Action ResumeRequested;
        public event Action<int, int> CellOpenRequested;
        public event Action<int, int> CellFlagRequested;

        private void Awake()
        {
            if (gameRoot == null)
            {
                gameRoot = gameObject;
            }
        }

        private void OnEnable()
        {
            AddButtonListeners();
        }

        private void OnDisable()
        {
            RemoveButtonListeners();
        }

        public void ShowGame()
        {
            gameRoot.SetActive(true);
        }

        public void HideGame()
        {
            gameRoot.SetActive(false);
        }

        public void ShowPause()
        {
            if (pauseRoot != null)
            {
                pauseRoot.SetActive(true);
            }
        }

        public void HidePause()
        {
            if (pauseRoot != null)
            {
                pauseRoot.SetActive(false);
            }
        }

        public void SetTimer(float seconds)
        {
            if (timerText != null)
            {
                timerText.text = Mathf.FloorToInt(seconds).ToString("000");
            }
        }

        public void SetMineCount(int minesCount)
        {
            if (mineText != null)
            {
                mineText.text = minesCount.ToString("000");
            }
        }

        public void RebuildBoard(IReadOnlyList<BoardCellData> cells, int width, int height)
        {
            ClearBoard();
            ConfigureGrid(width, height);

            for (var i = 0; i < cells.Count; i++)
            {
                CreateCell(cells[i]);
            }

            RefreshBoard(cells);
        }

        public void RefreshBoard(IReadOnlyList<BoardCellData> cells)
        {
            for (var i = 0; i < cells.Count; i++)
            {
                var cell = cells[i];
                if (cellsByCoordinate.TryGetValue(ToKey(cell.X, cell.Y), out var view))
                {
                    view.Render(cell, currentPixelsPerUnitMultiplier);
                }
            }
        }

        public void SetBoardInputEnabled(bool enabled)
        {
            boardInputEnabled = enabled;
            foreach (var cell in cellsByCoordinate.Values)
            {
                cell.SetInputEnabled(enabled);
            }
        }

        private void AddButtonListeners()
        {
            if (pauseButton != null)
            {
                pauseButton.onClick.AddListener(OnPauseClicked);
            }

            if (restartButton != null)
            {
                restartButton.onClick.AddListener(OnRestartClicked);
            }

            if (resumeButton != null)
            {
                resumeButton.onClick.AddListener(OnResumeClicked);
            }

            if (mainMenuButton != null)
            {
                mainMenuButton.onClick.AddListener(OnMainMenuClicked);
            }
        }

        private void RemoveButtonListeners()
        {
            if (pauseButton != null)
            {
                pauseButton.onClick.RemoveListener(OnPauseClicked);
            }

            if (restartButton != null)
            {
                restartButton.onClick.RemoveListener(OnRestartClicked);
            }

            if (resumeButton != null)
            {
                resumeButton.onClick.RemoveListener(OnResumeClicked);
            }

            if (mainMenuButton != null)
            {
                mainMenuButton.onClick.RemoveListener(OnMainMenuClicked);
            }
        }

        private void ConfigureGrid(int width, int height)
        {
            if (gridLayoutGroup == null || boardPanel == null)
            {
                return;
            }

            Canvas.ForceUpdateCanvases();

            var rect = boardPanel.rect;
            var panelWidth = rect.width > 0f ? rect.width : 512f;
            var panelHeight = rect.height > 0f ? rect.height : 512f;
            var padding = gridLayoutGroup.padding;
            var availableWidth = panelWidth - padding.left - padding.right - spacing * Mathf.Max(0, width - 1);
            var availableHeight = panelHeight - padding.top - padding.bottom - spacing * Mathf.Max(0, height - 1);
            var cellSize = Mathf.Floor(Mathf.Min(availableWidth / width, availableHeight / height));
            cellSize = Mathf.Max(8f, cellSize);

            gridLayoutGroup.constraint = GridLayoutGroup.Constraint.FixedColumnCount;
            gridLayoutGroup.constraintCount = width;
            gridLayoutGroup.spacing = new Vector2(spacing, spacing);
            gridLayoutGroup.cellSize = new Vector2(cellSize, cellSize);
            currentPixelsPerUnitMultiplier = Mathf.Clamp(basePixelsPerUnitCellSize / cellSize, 0.25f, 4f);
        }

        private void CreateCell(BoardCellData cell)
        {
            var go = new GameObject($"bt_{cell.X}_{cell.Y}_{cell.DisplayValue}", typeof(RectTransform), typeof(CanvasRenderer), typeof(Image), typeof(Button));
            go.transform.SetParent(gridLayoutGroup.transform, false);

            var labelGo = new GameObject("Text", typeof(RectTransform), typeof(CanvasRenderer), typeof(TextMeshProUGUI));
            labelGo.transform.SetParent(go.transform, false);
            var labelRect = (RectTransform)labelGo.transform;
            labelRect.anchorMin = Vector2.zero;
            labelRect.anchorMax = Vector2.one;
            labelRect.offsetMin = Vector2.zero;
            labelRect.offsetMax = Vector2.zero;

            var label = labelGo.GetComponent<TextMeshProUGUI>();
            label.alignment = TextAlignmentOptions.Center;
            label.enableAutoSizing = true;
            label.fontSizeMin = 6f;
            label.fontSizeMax = 32f;
            label.color = Color.black;

            var view = go.AddComponent<CellView>();
            view.Bind(go.GetComponent<Button>(), go.GetComponent<Image>(), label);
            view.Initialize(cell.X, cell.Y);
            view.SetInputEnabled(boardInputEnabled);
            view.OpenRequested += OnCellOpenRequested;
            view.FlagRequested += OnCellFlagRequested;
            cellsByCoordinate[ToKey(cell.X, cell.Y)] = view;
        }

        private void ClearBoard()
        {
            foreach (var cell in cellsByCoordinate.Values)
            {
                if (cell != null)
                {
                    cell.OpenRequested -= OnCellOpenRequested;
                    cell.FlagRequested -= OnCellFlagRequested;
                }
            }

            cellsByCoordinate.Clear();

            if (gridLayoutGroup == null)
            {
                return;
            }

            for (var i = gridLayoutGroup.transform.childCount - 1; i >= 0; i--)
            {
                Destroy(gridLayoutGroup.transform.GetChild(i).gameObject);
            }
        }

        private void OnCellOpenRequested(int x, int y)
        {
            CellOpenRequested?.Invoke(x, y);
        }

        private void OnCellFlagRequested(int x, int y)
        {
            CellFlagRequested?.Invoke(x, y);
        }

        private void OnPauseClicked()
        {
            PauseRequested?.Invoke();
        }

        private void OnRestartClicked()
        {
            RestartRequested?.Invoke();
        }

        private void OnResumeClicked()
        {
            ResumeRequested?.Invoke();
        }

        private void OnMainMenuClicked()
        {
            GoToMenuRequested?.Invoke();
        }

        private static int ToKey(int x, int y)
        {
            return (y << 16) ^ x;
        }
    }
}